The present disclosure relates to a light emitting device lighting-on/off control circuit in a light emitting display device in which light emitting devices, such as light emitting diodes, are arranged in a matrix.
Many of the copying machines or Multifunctional Peripherals (MFPs) (apparatuses having a combination of functions, such as those of printer, scanner, and facsimile) include a control part in which light emitting display devices (indicators) or buttons having a light emitting display function are arranged.
Generally, such a control part has a configuration in which LEDs (Light Emitting Diodes) or switches (such pushbutton switches) incorporating an LED are arranged on a control part substrate that is separated from a main control apparatus for the copying machine or the Multifunctional Peripheral (MFP).
For connection between such a control apparatus and a control part substrate, a connector or a flat cable is used, however, in order to reduce the number of signal lines, a scan matrix circuit in which a plurality of LEDs are arranged in a matrix is often formed on the control part substrate to control lighting-on/off of the LEDs.